HUE026420T2 - Explosion protection for non-electric device - Google Patents

Description

Explosion projection for «on-elcetric device

The salves* matter ofttjfc itaotiö:» iis aft explosion prefetai* fm » nopfefectrie device or unit that: is; hoi in the operating stats, in parilettafera; cehiritugai pump· for Hot delivery media;. DB-A-d Ö?§ :-643 discloses aft enclosed: madone unit in a noises and/or heat-insulated machine casing. The enclosed machine null: comprises a dlésef »tor and a: cohpressor vfeieh am arranged te a sound-absorbing «ssfeg, The inner wait of» easing is covernd -WÄ tansuf afiog material iapr. For ëoôîîog öl the und, » sstoer wail; is provided with cooling surfaces which are connected to a coolant supply. fiw explOsioft protection, in shorn ex-protectta for devices or units was based in the past substaatin% on the ex-protection-compiiam sefecta of electric components and now-sparking material combinations of devices. As ä result of a new European Directive (ED 94/fe E£j,: non-eisetrie devices am now also regarded as an ignition soufc" io tem® of their risk poseptial ta ©orrespoadlngiy memsm arererfgimdibr safe «se in the ox-tegidn. it mmt thus, among other things, hé ensured that the surface temperature of tsg device of unit lies hefew the maximum ipemtEsibieignitioo tentperature of the respective ex-region, 1rs this ease, the ignition tmaptaures are norataily divided Into temperature classes.

As: a result of fee feghfetions which tmw apply, measures for ex-protection must also be; taken In some cases isr centrifugal pumps with high: medium temperatures. Tins applies, tor example, to pumps, the medium temperature of which exceeds; 2iIE£, but which staid; be operated in temperature class 13 with a maxintntft pspnissihle tempefetum of 200°C. At its! glance,: various measures lend themselves to this but most: be rejected under certain eiremnstariees on various grounds: an isolation of the pump is not pernnssibk since a risk of' ignition could arise as a result of leakage and concentration; an effective talag of the pump by a ftagP italta wafer, tepuires m^t addfiiona] outlay which can often not be provided; a " vapmuMphiblting encapsulation" according; to European Standard EM 13463-3 can Icpoentiy not be used in certain ex-zones and as a result of fee complex geometry of the article to he sealed off ime objoei on which the Invention is based is thus to provide an explosion protection for a non-electric device or usit that is hot in the operating stipe, which ensures a high level of safety with little outlay.

The set object is achieved according to the invention by aa enclosure that only encloses partial regions, In particular a hoi stone, of the sorites of fee device of unit at a distance, wherein a non-explosive* best-dissipating gas linder positive pressure Is fed Into the enclosure and Is retnoved -from the enclosure by way of openings, wherein gaps remain betwbehfee surface of the device or unit and die enclosure.

Here, the invention relies on a fechtioiogy which is already known: ip terms of its principle, but was previously used tor other purposes and with a different configuration: tie encapsulation of tPäChihe tarifs which was used in particular to reduee noise emissioo. provided with a souod-msulatiog layer usually on its inner wall.

The earthed enofpsure, ptefembly emnposed of metal, of #se «woollen shields fee hot stirfece of the device or unit from tbs surroundings, wherein varions effects; arc generatedby the gas delivered into the: enclosure: an ex-free æone is generated around the device or unit. Since a positive pressure is generated In tbc enclosure hy the &as*:eo gas, j.e. alsç? su> exmtmosphsre, can penetrate· from the outside. On the mattsrÿ, a contipoys· flow of the delivered gas tb: tire outside: is ssahmhned, as a result of which: a continuous Saw for removing heat is aise : produced which in tulm keeps the surface temperfpre tif the enclosure below She reiptired threshold value.

The actuation offen umersghCé of the endettas is preferably: earned eut by ait Inert: gas. For sxanäple, nitrogen can he used asr or non-ex ambient air can also:heconducted by a suitable delivery systeokmm the enclosure.

The ranmyal of the hÄdheschias out of the enclosure: ctm: fee Pliait ·0«ί:ΐρ?^ί9|ίΐ0§ paratere and do various: paths. Ilers are preferably nm«mmämg. :$m enclosure. This has; fee advantage imf tempeinture-resistant seais between the hot surface and the enclosure can also be omitted such as & separate device for the removal of the gas introduced. in order to achieve increased: safety. It is recommended to provide a device for monitoring the surface fentperamre offec device and the enclosure. As a result ofthis, not only the adherence to à prascrebed maximum tetaperstnre is easaeOil Moreover, malts which can become notleedhle as a result of a t«taperatwe Increased can fee detected at an early stage, which in torn enables the transmission of a fault signal and/or the early switching off of the relevant: device or unit.

Moreover, a device fer moniforhm the pressura Inside the enclosure is recommended. This results In a warning device which respuds; very muly pod whiclg anfeUi; ofeef feings, already responds to an nnoaimtanf In the: delivery of the ps which removes the heat. An impermissibly high pressure build-up in the enclosure is prevented as a result of this.

Flnhlly, a de vice tor hmmmsieg any leakages of the de vice or unit can also: fee bene fie tal since feis also allows an early response to potential husks.

The invention will he: explained on the bas& of an ékefepfâîÿ embodiment The drawing: shows a centrifugal pump % driven % a separately set-up eieetyomotor 1, which centrifugal pump '% serves to deliver a medium: whipfe has a temperature of»teures hum 200°C.

As a result of Ike delivery medium which enters via a Action piece 3 and escapes via a pressure piece easing 5 of ecimifngsd pump'l is heated to a maximum vaine aller a ceriain period of delivery, which maximum value wouldi aiso fee above 3(111¾ in she absence of cooling. In order to be usable in ex-temperaiure: class T3. however, the sui'lace temperature exposed to atmospirere b of the unit crermosed of electromotor l and ceufrihigal pmnpT must not y speed the threshold of 200¾ at any point In order to sadsfy this : deliveryj: the: stnface: of casing 5 mast fee shielded; from atmosphere 6, Th is can seve:rthe)ess not; occur in a mmnier as in the esse of the pipes - ran represented here - connected to suction piece .¾ and pressure piece I of centrifugal pump i|, namely by m isolation attached to the surface. Were a leakage, 'which cannot be ruled: out wife cetiSmiy, namely to occur at pump casing .3, there would fee a risk of ignition.

The shielding;: off of csslogj ifota atmosphere $ is carried Out fey ah; enclosure 7 wkicir esdeaes the hot aonsand iaa ad|fefes|: cooler region of cemniuga! pump 2, without, however, haying: eonmet with the varions Anfefee regions, hraehial lact, there remain gaps 8 feet ween the: surface of caniriätgsl pump 2 and enclosure ?,

Enclosure ? forms an ex^proteeted space 9 which is giipplicd yin; a pipe fO with a non-explosive gas: lorn: a source,: not; represented, If is eustrred here that the pressure in: space: I is always above ike pressure of surrounding atkfesphere (I, Therefore, no air can flow out of the sumsmdings into enclosure 7. Above ail.

Claims (4)

1. however, s constant leakage of (be ps Eewiog oui: vis gaps 8 ont of space 9 lato the surroundings is produced. M a result of the also continuous sutep&ol flow of gas into ^aae 9, a coatfeoos gas flow Is thus geoenatel which removes part of tire heal present: ip spee f into surroundings d, The.initial teniperppe asd guana ty of the gas poshed into space 9 are selected so that the sarihoe temperature of enclosure 7 always remains below 200CC This is monitored with the aid of a -hemmcne-er 11:., The saflacetempraiure of pomp easing 5 is monitored by a thermometer 12. This monitoring allows an early response to arsy fehasfeean increase la the fetpfesi'b of the mediom is dfecfei earlier at this point thso at enclosure 7, MoSoovety the point io thne at which: enclosure 7 may he peced can be determined on the basis: of Éa itaiPpefeore measured hers: this is the case if the pump ietnpemmre Is i *5%'. or lower. flnai%, a pressure monitor ;T3 Is also t&d pressais: le spade 9 Is monitored, A felt: la the system which supplies the gas for space :¾ excessive: leakage oat of space 9 or an impermissible pressure &&&& :Sd'thM earl be; initiated Ιό a timely manner'. Eohhaaàsvédelem mm elektromos berendezdshez SZAÏ3ADALMI lOÉNYFObiTOi

   1. Robbandsvddelem rsem elekmmms, üaeml âllapoiban forré bereodezdsitez vagy aggregation, kitibubsen fefê kdgepi sfetM ôfeaysæÈvatfefeg (2), skzal jelkmeæve, bogy egy, a berendezés vagy aggregdt {2} feiüieiéoek esak ressert, eisosorbsn egy idrrd zônUt ibvkd&fe kbrbevevé burkolanr (7) van, ahoi egy nom roblfeâkéges,. a melaget eivszetô gâz van tàlayomsssai a barkoladsa (?) bevezesve es nyüâsokoïs (f| keresxtbi a harkoiatbdl (7) kivez.etve, aboi a berendezés vagy aggregât {2} fekdeie és a burkolat (?) kdzdil rés van.
2. 2. Az I, igènygpm: szsrintï Mbfefevedelem,: a«xsf jellemexve, hop inert: $g&; van a barkolaipa (7) bevezetve. % Az i. vagy 2. igénypont szAirioti robbamtsvédeiem, azmt jeitemezve, bogy a ixrvezeteft gâz elvezetesdreafe (SS) a herondezés vagy aipegst (2) ÉlSlete és a burkoiat (?) kßzött van etrendegve, Λ. Az 1. vagy 2. igénypom sxermls robbanasvédeiem, asssml jeSfemozvc, hop a berendezés .vagy aggregàt |2) feiSfeto Pa aferfeolat (?) Rbzhtti fe (8) pgy hMld szigeteid réteggel van tezâwa, aboi a. bevezfett gaz. eivezetésére egy ktlion berendezés szolgai,
3. 5. As elbzb igénypoîdok barmélyike szerinti robbanasvédeiem, aæzai jeilemezve, hop égy beteodezéssel fil, 12) vaneilatva a berendezés vagy aggregàt (2) (eiüietl hômérsékleténekelienörzisere. b. Az eteS igéayp®dok hâmseiyike szerimf robtpsésvédelgîn, azzai jelktaepe, hogy ep feerendezàsssi (13) vao eilâtvAa fekdlsti^a (?) iclièpê nyemôs ellenorzésCrc. ?. Az eîëzd Igéaypontok bémseiyike szertei robbanésvÉhïîem, aï*«l:^ifeei«*a^<'h0^p^''i^endp*^â: vao ellâtva a berendezés vagy aggregàs (2) esetiôgrcs sziviif gâsâoak ellenôrzésëre,
4. 8. Az eldzd Igdnypontok bdrmelyike sz.enoti robbanrlavrldelem, axzai jelkonezve, bogy a borkoia; (7) lembbl van es Ibidelt,